Reels are used in crop harvesting devices, particularly on cutting mechanisms, in order to deliver the standing crop to a cutter bar and a cross conveyor. They include a plurality of tine carriers (usually five or six) that extend across the width of the crop harvesting device.
U.S. Pat. No. 3,145,520 describes a reel that includes tine carrier tubes with tines mounted thereon. The tine carrier tubes are supported on spiders that are arranged on the respective tube ends and distributed over the width of the reel. The tine carrier tubes are rotatably supported on the spiders and turned by eccentric drive mechanisms in order to achieve the desired orientation of the tines. A central tube for providing the reel with the required stability extends across the central axis of the reel. This structure is a disadvantage because the central tube increases the weight of the reel and limits the operator's view of the cutting mechanism elements, particularly the cutter bar and regions located in front of the cutter bar.
U.S. Pat. No. 3,902,305 describes a mowing device with a flexible cutting belt for cutting standing crop. A reel located above the cutting belt delivers the crop to the cutting belt and consists of spiders at each end and tine carrier tubes extending between. A central tube can be eliminated in this device because the working width of the mowing device is relatively small. However, the lack of support between the ends of the tine carrier tubes makes this reel unsuitable for larger working widths.
In reels that are equipped with a central support tube and in which the tine carriers are supported between their ends by links connected to the support tube, such as U.S. Pat. No. 3,145,520 above, it is not required to make special provisions for fixing the links on the tine carriers in the axial direction, because the links are fixed on the support tube. If a reel according to U.S. Pat. No. 3,145,520 were not provided with a center support tube, axial guidance of the links would not be provided.
U.S. Pat. No. 6,397,573 describes a reel assembly in which the tine carriers are divided into tubular segments in the axial direction. The segments are fixed to one another by solid connecting shafts that are inserted into the ends of the segments and fixed therein with bolts or screws. The connecting shafts include a section of reduced diameter that serves to accommodate a support. This support is mounted on the outer ends of the arms, namely on the spiders of the reel that are connected to the central support tube. This reel assembly also contains a central support tube that has the disadvantage of high weight and a restricted field of vision.
A reel without a central support tube is described in republished DE 10 2004 001 383 A. In this reel, the tine carriers are connected to one another by links that form a supporting framework. The links form a hexagon, in the corners of which the tine carriers are rotatably supported.
In republished DE 10 2004 022 196 A, the links on the tine carrier are supported by carriers that are composed of bearing halves. The bearing halves are fixed to one another by the link that is pushed onto a link-carrying section located on the ends of the bearing halves. The bearing halves are axially fixed by annular holding elements that are respectively mounted on the tine carrier together with an adjacent tine.